Layered construction with tube system

ABSTRACT

The present invention relates to a device for collecting and utilizing energy generated by the sun, comprising a layered construction provided with a substrate layer and a cover layer comprising a curable mortar, wherein there is arranged on the substrate layer a tube system through which a fluid can be transported in order to regulate the temperature in the tube system, this tube system being at least partially embedded in the mortar, and wherein the mortar of the cover layer comprises insulating granules, cement, water and additives. The invention further relates to a method for manufacturing a layered construction for a device for collecting and utilizing energy generated by the sun.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/919,696, filed Feb. 18, 2011, which is a U.S. National Phase filingof International Application No. PCT/BE2009/000011, filed Feb. 26, 2009,designating the United States of America and claiming priority toBelgian Patent Application No. 2008/0110, filed Feb. 26, 2008. Thepresent application claims priority to and the benefit of all theabove-identified applications, and all the above-identified applicationsare incorporated by reference herein in their entireties.

DESCRIPTION

The present invention relates to a device for collecting and utilizingenergy generated by the sun in an efficient, environmentally-friendlyand sustainable manner, comprising a layered construction provided witha thermally insulating substrate layer and a cover layer comprising acurable mortar. The invention further relates to a method formanufacturing a layered construction for a device for collecting andutilizing energy generated by the sun.

The use of layered constructions with a view to thermal insulation of aspace is generally known, for instance in the construction of flatsroofs. The Belgian patent application no. 50599 thus describes aninsulating roof covering with ventilation. In addition, panels are alsoknown which serve as collectors for solar heat comprising channelscontaining a liquid heat-transporting medium. In these panels the solarheat is collected and transferred to the liquid medium. Such panelscannot however be used as substitute for a sufficiently strong andreliably insulated roof covering. A further problem with the knownpanels is that they substantially do not comprise any material that canretain the heat generated by the sun for a longer period of time, forinstance overnight.

The present invention has for its object to provide a device accordingto the preamble, which device can moreover be integrated in simplemanner into a building structure such as for instance a roof covering.

According to a first aspect, the present invention relates to a deviceaccording to the preamble, which device is distinguished in that thereis arranged on the substrate layer a tube system through which a fluidcan be transported in order to regulate the temperature in the tubesystem, this tube system being at least partially embedded in themortar. Owing to the use of the mortar-embedded tube system thetemperature can be regulated in simple manner while retaining theinsulating function of the construction.

The term “mortar” must here preferably be understood to mean apreferably curable material suitable for embedding of the tube system,preferably comprising at least cement and water. The person withordinary skill in the art will appreciate that other materials may alsobe suitable instead of such a mortar for the purpose of embedding thetube system. According to a further aspect of the present invention, thesubstrate layer comprises thermally insulating elements, these elementspreferably being embedded at least partially in a suitable substratematerial, preferably a suitable mortar. These elements are preferablybeam or panel-like and preferably have protruding parts in order tofacilitate incorporation thereof in the substrate layer. Theseinsulating elements improve the insulating properties of the substratelayer.

According to preferred embodiments of the present invention, thesubstrate layer comprises a substantially flat upper surface. This cansimplify or enable the arranging of tubes, tube system and cover layer.The tube system can preferably be arranged on the upper surface of thesubstrate layer without sinking into this substrate layer or withoutsinking into predefined recesses in the substrate layer. Nor is itnecessary to comprise or arrange a layer with high reflectivity, such asfor instance an aluminium foil or similar foil, between the substratelayer and the mortar. Embodiments of the present invention further alsocomprise the advantages that they can withstand frost damage andcondensation damage. A good adhesion between the cover layer and thesubstrate layer is also obtained in embodiments of the presentinvention.

According to a further aspect, a grid is arranged on the substrate layerin the layered construction, which grid preferably runs parallel to thesubstrate layer. The function of the grid consists substantially ofsimplifying placing of the tube system by securing the tube system in asuitable manner to the grid and of increasing the strength of thelayered construction.

The tube system preferably comprises a continuous flexible tube in orderto limit the chance of leakage of the fluid to a minimum. The tubesystem can further also be formed from a plurality of tubes joinedtogether, preferably in watertight manner. The tube system preferablyforms part of a closed liquid circuit and is watertight. In addition,the tube system is preferably connected to the grid. The tube system canfurther also increase the strength of the layered construction.

According to yet another further aspect of the present invention, atleast one heat exchanger is connected to the tube system by means ofsuitable feed and/or discharge conduits in order to enable heat to beextracted from and supplied to the fluid in the tube system for thepurpose of enabling regulation of the temperature in the tube system. Atleast one heat pump can also be connected in suitable manner to the tubesystem in order to recuperate the heat collected in the fluid.

According to yet another aspect of the invention, one or more storagevessels suitable for storing the fluid can be connected to the tubesystem by means of suitable feed and/or discharge conduits. In anotheraspect of the invention means are connected to the tube system for thepurpose of transporting the fluid. The fluid can be transported by meansof for instance a suitable pump through the tube system and devicesconnected thereto. According to a further aspect of the presentinvention, the layered construction can be part of a building structure,in particular an outside wall, a roof covering or a paving, wherein afinishing layer is applied to the cover layer. This finishing layer hasthe purpose of protecting the building structure in its normal functionfrom external influences (such as for instance rain and wind) and/orproviding an aesthetic finish. The finishing layer is preferably thinand preferably has a relatively limited heat resistance. Depending onthe finishing layer, an air layer or a number of air channels can beprovided between the cover layer and the finishing layer.

It is also an object of the present invention to provide a method formanufacturing a layered construction for a device for collecting andutilizing energy generated by the sun.

The layered construction is preferably placed at a location readilyaccessible to direct sunlight, oriented as far as possible toward thesun. The device can herein form part of a building structure in the formof a roof covering, an outside wall or a paving, such as for instance adriveway. The temperature in the layered construction, in particular ofthe mortar, can then be increased by solar radiation.

The temperature of the fluid can here then be increased substantially bythermal conduction from the heat-accumulating mortar which encloses thetube system to the fluid present therein. The advantage of using themortar is that the heat can be retained therein for a long time, and canconsequently also be generated to the fluid in the tube system for along time. Even when there is no longer any direct sunlight shining onthe device, heat can nevertheless still be generated to the fluid for along period of time, for instance after sunset, due to the heat storagein the layered construction.

The device can be placed substantially vertically or substantiallyhorizontally, or can be arranged at an incline. It is an advantage ofembodiments of the present invention that the device iswater-impermeable, this being particularly important when the device isplaced horizontally during use.

The device according to embodiments of the present invention furtheralso comprises the advantage that it can bear a substantial load withoutbeing damaged. Adult persons can thus walk on the upper surface of thedevice and move about thereon without damaging this device. Theinvention will be further described with reference to the accompanyingfigures, which are not in any way intended to limit the scope ofprotection of the claims and in which:

FIG. 1 shows a partly perspective section of a preferred embodiment of alayered construction according to the present invention on a groundsurface, bounded on one side by an upright wall;

FIG. 2 shows a schematic outline of a preferred embodiment of the tubesystem as preferably closed liquid circuit according to the presentinvention;

FIG. 3 shows a further preferred embodiment.

In the preferred embodiments shown in FIG. 1 a layered construction 1 isplaced on a ground surface 2, consisting of for instance concrete, andflanked by an upright wall 3 formed by for instance a wall of bricks.The layered construction comprises a substrate layer made up of asuitable substrate material 4, preferably a curable mortar, and aplurality of thermally insulating elements 5.

The curable mortar preferably comprises insulating granules, cement,water and additives. The composition of the mortar is a furtherpreferably chosen such that the mortar has at least thixotropicproperties. The mortar preferably also has a high heat capacity combinedwith a coefficient of heat conductivity of preferably between about 0.05and about 0.30 W/mK, more preferably between about 0.10 and about 0.25W/mK, still more preferably between about 0.15 and about 0.20 W/mK, inorder to have a balance between insulation and conductivity. Theinsulating granules are preferably chosen from expanded polystyrenegranules, polyurethane granules, expanded polyurethane granules,preferably expanded vermiculite, preferably expanded perlite andcombinations thereof.

In the preferred embodiment shown in FIG. 1 the substrate layer isfurther provided with thermally insulating elements 5 preferably formedfrom beam or panel-like blocks of insulation material having thermallyinsulating properties. Suitable materials for these thermally insulatingelements comprise for instance expanded polystyrene, extrudedpolystyrene, polyurethane, expanded polyurethane and combinationsthereof. Various other suitable thermally insulating materials are knownto the person with ordinary skill in the art in this field. Thesethermally insulating elements optionally form part of the substratelayer. Further arranged on top of the substrate layer in the embodimentof FIG. 1 is a grid 6 to which a tube system 7 is secured by means ofmetal or plastic strips or wires 8. According to a preferred embodiment,the grid is formed from suitable metal and/or suitable plastic. Examplesof suitable metals are iron, aluminium, stainless steel and so forth.Examples of suitable plastics are polyethylene, polypropylene, polyvinylchloride (PVC), glass fibre reinforcement or a composite of two or moreof such materials, optionally combined with metal and so forth. Variousother suitable materials are known to the person with ordinary skill inthe art in this field. The grid can possibly consist of a plurality ofparts or part-grids. Tube system 7 can be secured to grid 6 in variousother suitable ways known to the person with ordinary skill in the art.Various suitable materials from which the tube or tubes forming part oftube system 7 can be formed are known to the person with ordinary skillin the art in this field. Examples of suitable materials comprisepolyethylene, medium-density polyethylene, high-density polyethylene,polypropylene, PVC, cross-linked polyethylene (PEX), metals such ascopper and aluminium and so on. The tube or tubes can possibly also beformed from combinations of such materials. The tube or tubes canoptionally be formed from multiple layers of various such materials. Inthe embodiment shown in FIG. 1 the tube system 7 forming part of thelayered construction is completely embedded in a cover layer 9preferably formed from a curable mortar. The mortar forming part ofcover layer 9 more preferably has a composition similar to the mortarforming part of the substrate layer. In the shown embodiment a finishinglayer 10 is further applied over cover layer 9. This finishing layer 10can lie at a distance relative to cover layer 9 in order to form an airlayer or air channels.

According to a more preferred embodiment (shown in FIG. 3) , tube system7 lies substantially flush with the outward facing surface of coverlayer 9 and thus lies closer to finishing layer 10. This can be achievedfor instance by levelling off the cover layer, after applying the coverlayer material, on the tubes of the tube system so that the uppersurface of the cover layer forms as it were a tangent plane on the topside of (the tubes of) the tube system. The heat can hereby be collectedmore efficiently by the fluid in tube system 7. When the finishing layerdoes not run parallel to the substrate layer, the tube system preferablyruns substantially parallel to the finishing layer in order to obtainthe highest possible efficiency in heat absorption by the fluid. The oneor more tubes forming the tube system can have a diameter of forinstance about 1, 2 or 3 cm. Higher and lower values for the diameterare also possible. The thickness of the finishing layer can for instanceamount to about 2, 3, 4, 5 or 6 cm. Higher and lower values for thethickness of the cover layer are also possible. The fluid must besuitable for absorbing, generating and transporting heat. The fluid ispreferably non-toxic. A suitable fluid is for instance composed of waterand one or more preferably non-toxic additives. These additives can forinstance serve to prevent freezing of the fluid and/or to preventcorrosion. An example of a suitable non-toxic antifreeze agent is forinstance polypropylene glycol.

The material of which finishing layer 10 consists is chosensubstantially subject to the purpose of the device. The device can thusbe placed for instance on flat roofs as well as sloping roofs. When thelayered construction is arranged as part of a substantially flat roof(this is a roof with a maximum slope of about 5%) the finishing layerconsists for instance of a prefabricated strip-like or tarpaulin-likewaterproofing made up of one or more layers, such as for instance EPDM(Ethylene Propylene Diene Monomer) PVC, APP (AtacticPolypropylene)-modified bitumen, SBS (Styrene ButadieneStyrene)-modified bitumen and combinations thereof. When the device isplaced as part of a sloping roof, the finishing layer can for instanceconsist of tiles, slates, metal panels, zinc strips and so forth. Itwill be apparent that various other materials are possible as finishinglayer which are known to the person with ordinary skill in the art. Thefinishing layer is preferably thin and preferably has a relativelylimited heat resistance of preferably <0.5 m<2>K/W, more preferably<0.25 m<2>K/W, still more preferably <0.1 m<2>K/W, and most preferably<0.05 m<2>K/W. FIG. 2 shows a schematic outline of a preferredembodiment of the tube system substantially of the device of FIG. 1,wherein numeral 11 refers to one or more heat exchanger(s), heat pump(s)and/or storage vessel(s) and other possible devices which can beconnected by means of suitable feed and/or discharge conduits to thetube system.

Means (12), such as for instance a pump, are also connected to the tubesystem in order to transport the fluid through the tube system anddevices connected thereto.

Heat-generating devices can optionally also be connected to the tubesystem for the purpose of heating the fluid before it is transportedthrough the tube system. In addition, the tube system can optionallyalso be connected in suitable manner to one or more classic panel-likesolar collectors, with the object of preheating the fluid before it iscarried through the solar collector. The present invention also providesa method for manufacturing a layered construction for a device forcollecting and utilizing energy generated by the sun, comprising ofarranging a substrate layer on a suitable ground surface, such as forinstance concrete or fibre cement sheets, arranging a tube system andarranging a cover layer. According to a preferred method, the substratelayer is manufactured by arranging a layer of a substrate material,preferably a curable mortar preferably comprising insulating material,subsequently placing thereon at a mutual distance elements of insulationmaterial preferably preformed into blocks, and then filling the spacebetween the blocks by means of a curable mortar preferably comprisinginsulating material.

According to a preferred method, after arranging of the substrate layer,the grid is placed on this layer, preferably parallel thereto. The tubesystem is then preferably arranged on the grid. The tube system is herepreferably secured to the grid so that the tube system is displaced toonly minimal extent during arranging of the cover layer. The cover layeris preferably then arranged by pouring or casting a curable mortar,whereby the tube system is further connected to the substrate layerand/or the grid. The tube system preferably lies substantially flushwith the surface of the cover layer. A finishing layer can subsequentlybe further arranged on the cover layer.

The layered construction is preferably manufactured on a constructionsite. The advantage hereof is that it is then not necessary to work withseparate panels, thereby reducing the chance of leakage or insufficientwaterproofing of the device. Alternatively, the layered construction canbe fabricated in the form of panels, optionally with the tube system ora part thereof integrated. The tube system or a part thereof and thegrid or a part thereof can optionally be manufactured integrally in thefactory and thus employed in the manufacture of a preferred embodimentof the device according to the present invention. Since according to apreferred embodiment the part of the tube system intended forarrangement in the layered construction is at least partially embeddedin the mortar, heat can still be generated to the fluid even forinstance after solar radiation no longer impinges on the layeredconstruction, since the heat can be held in the mortar for a long time.

An advantage of a preferred embodiment of the device according to thepresent invention is that the heat generated by the sun can be usefullyemployed in an efficient and economic manner, for instance to increasethe temperature of a building structure, of a space or of a mass. Thisheat can for instance be utilized for a central heating system, to heatfloors, to heat swimming pool water, to heat determined rooms in abuilding and so on.

A further advantage of a preferred embodiment of the device according tothe present invention is that it can be used to control the temperaturein a building structure of which the layered construction forms part. Inadvantageous manner the temperature in the layered construction in thebuilding structure, and consequently also in spaces adjacent thereto,can thus be reduced if this is desirable by supplying fluid at a lowertemperature to the layered construction and discharging fluid at ahigher temperature therefrom. In this way heat can be discharged fromfor instance a roof covering in order to reduce the temperature of theroof construction, whereby the underlying space will be heated lessquickly. A further advantage of preferred embodiment of the deviceaccording to the present invention can consist of bringing the layeredconstruction to a higher temperature during a colder period using theheat stored in the meantime. This results in a smaller difference intemperature between the outside of the building structure (so-called“heat loss area”) and the indoor climate. This smaller temperaturedifference also results in a reduced energy loss from the indoorclimate.

1. A device for collecting and utilizing energy generated by the sun,said device being suitable for a roof-covering, said device comprising alayered construction provided with a substrate layer and a cover layercomprising a curable mortar, wherein there is arranged on the substratelayer a tube system through which a fluid can be transported in order toregulate the temperature in the tube system, this tube system being atleast partially embedded in the mortar, wherein the mortar of the coverlayer comprises insulating granules, cement, water and additives; andwherein the tube system is arranged on a surface of the substrate layerwithout sinking into this substrate layer or without sinking inpredefined recesses in the substrate layer.
 2. The device of claim 1,wherein the insulating granules comprise expanded vermiculite andexpanded perlite.
 3. The device of claim 1, wherein the tube system islargely or completely embedded in the mortar.
 4. The device of claim 3,wherein the tube system lies substantially flush with the outward facingsurface of the cover layer.
 5. The device as claimed in any of the claim1, wherein the substrate layer is a thermally insulating substratelayer.
 6. The device of claim 1, wherein the mortar has a coefficient ofheat conductivity of between about 0.05 and about 0.30 W/mK.
 7. Thedevice of claim 2, wherein the insulating granules further comprise atleast one of expanded polystyrene granules and polyurethane granules. 8.The device of claim 1, wherein the substrate layer comprises thermallyinsulating elements which are embedded at least partially in a mortar.9. The device of claim 8, wherein the thermally insulating elements areformed from at least one of expanded polystyrene, extruded polystyrene,and polyurethane.
 10. The device of claim 1, wherein the tube systemcomprises a continuous flexible tube.
 11. The device of claim 1, whereina grid running substantially parallel to the substrate layer is providedon the substrate; wherein the tube system is connected to the grid. 12.The device of claim 1, wherein the device is a part of a roof covering,wherein a finishing layer is applied to the cover layer; wherein thefinishing layer has a heat resistance which is smaller than 0.5 m²K/W;and wherein an air layer or a number of air channels is provided betweenthe cover layer and the finishing layer.
 13. A device for collecting andutilizing energy generated by the sun, said device being suitable for aroof-covering, said device comprising a layered construction providedwith a substrate layer and a cover layer comprising a curable mortar,wherein there is arranged on the substrate layer a tube system throughwhich a fluid can be transported in order to regulate the temperature inthe tube system, this tube system being at least partially embedded inthe mortar, wherein the mortar of the cover layer comprises insulatinggranules, cement, water and additives; and wherein the tube system isarranged on a surface of the substrate layer without sinking into thissubstrate layer or without sinking in predefined recesses in thesubstrate layer; wherein the insulating granules comprise expandedvermiculite and expanded perlite.
 14. The device as claimed in any ofthe claim 13, wherein the substrate layer is a thermally insulatingsubstrate layer.
 15. The device of claim 13, wherein the mortar has acoefficient of heat conductivity of between about 0.05 and about 0.30W/mK.
 16. The device of claim 13, wherein the insulating granulesfurther comprise at least one of expanded polystyrene granules andpolyurethane granules.
 17. The device of claim 13, wherein the substratelayer comprises thermally insulating elements which are embedded atleast partially in a mortar.
 18. A method for manufacturing a layeredconstruction for a device for collecting and utilizing energy generatedby the sun, said device being suitable for a roof-covering, comprisingthe steps of: arranging a cover layer on a substrate layer, the coverlayer comprising a curable mortar, wherein the mortar of the cover layercomprises insulating granules, cement, water and additives; arranging atube system through which a fluid can be transported on the substratelayer, wherein this tube system is at least partially embedded in themortar; and wherein the tube system is arranged on a surface of thesubstrate layer without sinking into this substrate layer or withoutsinking in predefined recesses in the substrate layer.
 19. The method ofclaim 18, wherein the insulating granules comprise expanded vermiculiteand expanded perlite.
 20. The method of claim 18, wherein the substratelayer is formed by arranging liquid curable mortar, placing thereon at amutual distance elements of insulation material preformed into blocks,and filling a space between the blocks with the mortar.